The present invention generally relates to performance analysis of data processing systems, and more particularly to analyzing the input/output operations performed by a data processing system.
Various performance characteristics of data processing systems are modeled to demonstrate the capabilities of different system configurations. For example, the number of instructions/second executed by the system may be particularly relevant for some applications, while the number of input/output operations/second may be of interest for other applications. Hardware and software vendors often use proprietary tools to model a system""s performance and estimate a performance increase when new hardware and/or software is added to the system.
In one example, Unisys Corporation uses a modeling tool to determine whether an outboard file cache, such as the Extended Processing Complex (XPC) product from Unisys, would enhance system performance. To use the model, the customer supplies a record of all input/output operations that occurred during a period of time for a present system. The record of input/output operations is referred to as the I/O trace file. The I/O trace file is then processed using he model to determine the performance level of the system with the addition of an outboard file cache.
It may be desirable to analyze the I/O trace file prior to modeling the system. This can be useful in identifying patterns associated with request types or locating blocks of I/O requests that are of particular interest to a user. For example, a user may be interested in a certain block or group of blocks of I/O requests and may desire performance analysis to be performed only on those blocks.
Viewing I/O trace files has often been difficult because the files are very large. Many conventional editors cannot read the entire trace file into memory. Thus, a common method to view the trace file has been to translate the trace file into a printable file, which can then be viewed either electronically or printed to obtain a hardcopy.
Electronically viewing a printable file is difficult for several reasons. First, I/O trace files are approximately 132 columns wide, and therefore, viewing can be awkward. Additionally, the data is binary, which without translation may be difficult to comprehend. Therefore, it can be time-consuming and difficult to locate particular I/O operations or blocks in the trace file.
A method that addresses the aforementioned problems, as well as other related problems, is therefore desirable.
A method for analyzing input/output operations of a data processing system is provided in various embodiments of the invention. In one embodiment, the method comprises storing input/output trace data of the system in an input/output trace file. The trace file is interactively analyzed by first interactively obtaining data selection criterion and then reading input/output trace data from the trace file in accordance with the selection criterion. The input/output trace data read from the trace file is displayed, and the steps of obtaining the data selection criteria and displaying the trace data are repeated.
The above summary of the present invention is not intended to describe each disclosed embodiment of the present invention. The figures and detailed description that follow provide additional example embodiments and aspects of the present invention.